CH635244A5 - SURGICAL SEWING MATERIAL WITH IMPROVED KNOTTING PROPERTIES. - Google Patents

Description

The invention relates to a surgical suture material 15 which is provided with a coating which improves the knotting properties. The suture material is, in particular, synthetic, absorbable multifilament threads. The invention further relates to a method for producing such surgical sutures. Surgical sutures are classified as either absorbable or non-absorbable, with each type of surgical suture being preferred for certain uses. The absorbable sutures are preferred for those applications in which the sutured tissues hold together after healing without the supportive effect of the suture, and in which a non-absorbed suture has the potential for a long-lasting adverse body reaction. Surgical sutures are said to be absorbable if they disappear from the sutured tissue within one year of surgery, with most absorbable sutures preferably disappearing in less time.

The most commonly used absorbable surgical sutures are catgut and extruded collagen-containing materials. More recently, sutures made of synthetic polymers have been developed that are absorbable, firm, uniform and dimensionally stable, can be stored in a dry state, and can be sterilized. Typical polymers of this type are lactide homopolymers and copolymers, such as those described in US Pat. No. 3,636,956 and glycolide homopolymers, such as those described in US Pat. No. 3,297,033, reference being expressly made to these patents 45 .

Monofilament, synthetic, absorbable surgical sutures are generally stiffer than the corresponding materials made of catgut or collagen, so that the synthetic, absorbable, surgical sutures are usually used in the form of a braided, multifilament structure. Such multifilament sutures show in terms of their "knotting" behavior, i.e. the property of how easy or how hard a knot can be pulled down the suture to the knot, a certain amount of unwanted roughness or unwanted "picking".

Multifile, non-absorbable surgical sutures, such as braided sutures made of polyethylene terephthalate, can be improved in knotting behavior by applying solid polytetrafluoroethylene particles and a binder resin to the outer surfaces of the suture, as described in U.S. Patent No. 3,527,650 is described. However, this approach is undesirable in relation to its application to absorbable sutures because polytetrafluoroethylene is not absorbed and the sutures coated with it would leave a residue in the sewn tissue.

Multifilament, non-absorbable surgical sutures can also be improved in their knotting behavior by coating them with a linear polyester that has a molecular weight between about 1000 and about 15,000 and has at least two carbon atoms between the ester bonds in the polymer chain. It is known that the above-mentioned polyesters can be used to coat absorbable synthetic surgical sutures, but does not take into account the fact that surgical sutures coated in this manner cannot be fully absorbed.

In the aforementioned U.S. Patent 3,297,033, it is disclosed that the synthetic absorbable surgical sutures described can be coated with coating materials used for conventional sutures such as silicone wax or beeswax to modify their handling properties or their absorption rate. These coating materials or covering materials are not absorbed and thus leave an undesirable residue in the fabric after the suture material has been absorbed as such.

The object of the present invention is therefore to provide surgical sutures with an absorbable covering, in particular for multifilament braided, twisted or covered surgical sutures, whereby the smoothness and the knotting properties of such surgical sutures can be improved, so that a completely absorbable, coated, receives synthetic, in particular multifilament, surgical suture material which exhibits good knotting properties or can be tied with the knot, which easily slide along the suture material to the desired location.

The subjects of the invention are defined in the independent claims.

The liquid preparations suitable for producing the coating can be mixtures which are completely in the form of a single liquid phase, for example in the form of a solution of all constituents of the absorbable coating preparation in a solvent or a solvent system, or are in the form of a single melting phase, all of which Contains ingredients of the preparation. Preparations are also possible which represent uniform dispersions of liquids which are immiscible with one another or solids in liquids.

Each of the components of the coating preparation performs its own function in the system. The lubricant provides the slipperiness that is required so that the contacting suture surfaces can slide past each other when knotted. The film-forming polymer is a binder that holds the lubricant and the hydrophobic material on the surface of the suture material and prevents them from shifting due to the friction that occurs during the knotting. The hydrophobic material prevents the coating from over-wetting when the surgical suture is pulled through the moist living tissue and thus prevents the change in properties resulting from such wetting.

Further advantages and embodiments of the invention result from the following description, the examples and the drawings.

The drawings show in Fig. 1 a schematic representation of a tensile tester for determining the knotting behavior and shows

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two braided suture strands arranged for the test procedure;

FIG. 2 is an enlarged perspective view of the single-loop knot shown in FIG. 1; and s in Fig. 3 is a typical recording image of a registering oscillograph used in the knotting studies.

The coating preparations according to the invention can be applied to any surgical suture material whose fiber slidability and knotting properties are to be improved. Preferred surgical sutures are synthetic, absorbable, multifile surgical sutures, which in particular comprise polylactide, polyglycolide and copolymers of i5 lactide and glycolide with one another or with other reactive monomers, as are described, for example, in US Pat. Nos. 3,636,952 and 2,683,136 . These preferred surgical sutures are referred to in the following in certain cases for the sake of simplicity as homopolymers and copolymers of lactide and glycolide.

The coating or the coating is preferably applied in the form of a liquid (or liquid-like) coating preparation to the suture surfaces 25, after which the coating preparation is solidified. The liquid or liquid-like preparation generally contains a solution of a film former, a lubricant and a hydrophobic material in a volatile solvent, the solidification being brought about by volatilizing the solvent. In those cases where the suture substrate solvent used in the coating formulation is not a solvent or substantially no solvent, the coating is deposited in the form of a distinct layer with a sharp interface between the coating and the substrate. If the solvent used in the coating formulation partially dissolves the suture substrate, the substrate softens or swells before drying so that the final product shows a more gradual transition from the composition of the substrate to the composition of the coating.

The coating solution can be applied to the surgical suture in any suitable manner, for example, by moving the suture 45 through a container containing the solution, or past a brush or applicator moistened with the solution, or one or more of the solution in the form of droplets distributing spray nozzles.

Instead of a coating solution, the liquid or liquid-like coating preparation can comprise a melt of the components, in which case the solidification is brought about by cooling. The melt should of course be kept at a temperature 55 below the melting temperature of the suture material, this technique can only be used if

when the preparation melts at relatively low temperatures.

The coating formulation may also be a suspension or a dispersion of particles of one or more of the three components of the final coating in water or a volatile organic solvent, while the remaining components of the coating (if still present) are in solution.

65 Instead of a liquid or liquid-like coating preparation, the preparation can also be in the form of a solid which is applied to the suture material by removing the suture material from blocks from the

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coating preparation passes over or between such blocks, the coating preparation being transferred to the surface of the suture material by a friction effect.

When coating multifilament suture materials with the preparations used according to the invention, it is not necessary for each thread of the suture material to be coated individually or completely. In most cases, however, the coating preparation penetrates the suture structure, especially when the coating preparation is applied in the form of a liquid or liquid-like preparation.

The film formers for the coating preparations used according to the invention are: homopolymers and copolymers of lactide and glycolide, i.e. Polyactide, polyglycolide and copolymers of lactide and glycolide with one another or with other reactive monomers; Copolymers of vinyl acetate with unsaturated carboxylic acids, such as crotonic acid, acrylic acid and methacrylic acid; water-soluble or water-dispersible cellulose derivatives, such as methyl cellulose, hydroxymethyl cellulose and carboxymethyl cellulose; natural gums or resins; high molecular weight crystalline ethylene oxide polymers; Polyacrylamide; Collagen; Gelatin; Polyamino acids; Polyvinyl alcohol; Polyvinyl pyrrolidone and absorbable, conjugated unsaturated triglycerides, such as dehydrated castor oil.

In the case of surgical sutures which consist of homopolymers or copolymers of lactide and glycolide, the film former in the coating preparation can be a polyglycolide, polylactide or a lactide-glycolide copolymer which has different proportions and different solubility properties with respect to the surgical suture material. For example, a surgical suture made from a lactide-glycolide copolymer that contains about 10% dilactyl residues can be coated with a preparation that contains a lactide-glycolide copolymer that contains about 65% dilactyl residues as the film former, since this copolymer is in Solvents such as benzene, dioxane or 1,1,2-trichloroethane are more soluble than the sutures.

If desired, the film former used in the coating preparation can have the same composition as the suture material, provided that precautionary measures are taken to prevent the suture material from dissolving when the coating preparation is applied. This can be done by using a coating composition comprising the film former in the form of a finely divided suspension in a non-solvent liquid, or by using a coating preparation containing the film former in the form of a solution with substantially the saturation concentration, and before maintains a short contact time between the suture material and the coating preparation when the solvent is expelled.

If the compositions of the suture and the film former are identical, and in those cases in which some dissolving and / or swelling or softening of the surface of the suture occurs due to the action of the solvent for the film former, instead of one results, as already stated sharp interface between the substrate and the coating a gradual transition from the substrate composition to the coating composition. There may also be a certain weakening of the suture material by applying such coating preparations.

The lubricant of the coating preparation is a

Polyalkylene glycol with a molecular weight of less than 200,000. Suitable polyalkylene glycols include the homopolymers and the copolymers of ethylene oxide and propylene oxide. Poly-5 ethylene glycol with a molecular weight of 4,000 to less than 200,000 and more preferably of 5,000 to 50,000 is particularly preferred.

Molecular weights are given herein as a weight average.

The hydrophobic material of the coating preparation is a higher fatty acid, which preferably contains more than 12 carbon atoms, such as stearic acid, or an ester of such a fatty acid, such as sorbitan tristearate and hydrogenated castor oil.

The range of the proportions of the components of the coating preparation can vary depending on the components selected and the desired coating properties. A suitable range of amounts for the film former is from about 10 to 50 percent by weight of the solidified coating, while the appropriate range of amounts for the hydrophobic agent is from about 10 to about 40 percent by weight of the solidified coating and the appropriate range for the Move the amount of lubricant from about 20 to 60% by weight of the solidified coating.

The proportion of the liquid dispersing medium in the coating preparation can range from zero (if the preparation is applied in the form of a solid or a melt) to an amount which is sufficient to give an easily flowable preparation, but not is so high that it becomes difficult or costly to evaporate the medium during the formation of a solidified coating. Amounts of the dispersing liquid of about 70 to about 97% by weight, based on the 35 weight of the applied coating preparation, are used in coating preparations which are used in the form of solutions or suspensions.

If desired, the coating preparation may contain, in addition to the ingredients described above, other ingredients for other useful purposes, such as dyes, antibiotics, antiseptics, anesthetics and anti-inflammatory agents.

The amount of coating preparation applied or the coating thickness depends on the structure of the fiber, i.e. the number of threads and the strength of the braided or twisted material, and 45 the type of coating material, i.e. whether it is used in the form of a melt, a solution or a solid. In general, a liquid or liquid-like coating preparation applied to a braided suture material makes up about 5 to about 10% by weight of the fiber coated in this way, although the amount of coating preparation applied also only amounts to about 1% by weight and up to about 15% by weight. -% or in some cases more. For practical reasons and for economic and general considerations, it is generally preferred to apply the minimum amount of coating preparation necessary for good knotting properties, this amount or coating thickness being readily experimentally determined for any given fiber coating system can determine.

60 The improvement in knotting properties conferred on synthetic, absorbable surgical sutures can be demonstrated qualitatively and organoleptically by comparing the grip of the coated and uncoated sutures during knotting or tying. This comparison is preferably made using both wet and dry surgical sutures, since many surgical sutures are examined in dry

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or wet condition have different knotting properties.

The improvement in the knotting properties achieved according to the invention can also be determined quantitatively with the aid of a test, for which purpose the device shown in FIG. 1 is used.

The quantitative determination of the knotting properties or the behavior when tightening the knot can be carried out with the aid of a tensile tester (table model INSTRON Tensile Tester) using a tensile cell type B, whose full measuring range is 100 to 2000 g. The device used here (INSTRON) is manufactured by the Instron Corporation of Canton, Massachusetts, USA. Instead of the standard recording device (Instron recorder), which would be too slow to track the rapid changes in force that occur during the examination when the sutures slide against each other, a high-speed oscilloscope (SANBORN Oscillographic Recorder (Model 7702A, manufactured by Hewlett-Packard, Wal -tham, Massachusetts, USA) To connect this recorder to the Instron transducer, a high gain DC amplifier (Hewlett-Packard Model 8803A manufactured by Firmai Hewlett-Packard, Waltham Division, Wal-tham, Massachusetts) is used , USA) and uses a low voltage DC voltage source to excite the measuring transducer. The measurements are carried out in an air-conditioned laboratory at a temperature of 22.2 ° C (72 ° F) and a relative humidity of 50%. To hold the suture strands used as samples one uses a jaw with line contact D The tensile tester is operated at a crosshead speed of 127 cm per minute (50 inches per minute), while the paper feed speed of the registering oscillograph is 20 mm per second.

In the subjective investigations regarding the knotting behavior, the suture arrangement 11 shown in FIG. 2 is used (i.e., a single loop knot in which each suture is looped over, under and over the other suture). The same arrangement results with the aid of a pulling device which is carried by the steel plate 10 shown in FIG. 1. The steel plate is attached to the crosshead 12 of the tensile tester (Instron tester).

To carry out the determination of the knotting properties or the behavior when tightening the knot, two strands 8 and 9 made of the same suture material are attached at one end to the transducer 14 of the type B cell of the tensile tester (Instron tester). The sutures, as shown in Figs. 1 and 2, are threaded into the traction device. The other ends of the suture strands are brought together, passed around the pulling rollers 15 and 16 and fastened together to a weight 18 which exerts a tension on the single-loop knot. The standard method uses a weight of 1.13 kg (2.5 pounds).

3 shows typical recording traces of a braided, synthetic, absorbable surgical suture material before and after the coating according to the invention in order to improve the knotting behavior. The «roughness values» are measured along the ordinate and given in kg (pounds) (roughness). When comparing relatively smooth samples, the amplitude of the recording oscillograph can be increased by a factor of 20.

The roughness values of uncoated, braided, synthetic, absorbable size 2-0 surgical sutures determined in the above test generally range from about 2.27 kg to about 3.63 kg (5 to 8 pounds). After the coating according to the invention, the roughness values of the dry seam materials are usually below approximately 0.91 kg (2 pounds) and, in optimal embodiments, below approximately 0.45 g (1 pound). If the sutures are examined in water for one minute after immersion in water at 25 ° C., the roughness values of the sutures according to the invention are usually below about 1.81 kg (4 pounds) and in optimal embodiments below about 1.36 kg (3 pounds).

The following examples serve to further explain the invention.

15 Example 1

60 parts by weight of a vinyl acetate / crotonic acid copolymer (90/10), 60 parts by weight of hydrogenated castor oil and 30 parts by weight of solid polyethylene glycol (with a molecular weight of about 20,000) are dissolved in 1350 parts by weight of 20 1,1,2-trichloroethane with stirring and maintaining a temperature of about 35 ° C so that a solution with a total solids content of 10 wt .-% (weight / weight) is obtained. Then, a tempered, braided suture of size 2-0 prepared from an L - (-) - lactide / glycolide copolymer (molar ratio = 10/90) 25, consisting of 19 bundles of 10 threads each (three a core forming yarn bundles and 16 carrier yarn bundles braided around the core) over drawing rolls at such a speed through a bath of this solution 3o (which, in order to keep the materials in solution, is kept at a temperature of 30 to 35 ° C.) that a Immersion time of about 6 seconds results. The braided suture is immediately passed through a drying tower to remove most of the solvent. The drying is completed by winding the coated fibers on a spool and subjecting them to a vacuum of 100 (in mercury) for several days in a vacuum oven. It is found that the solids absorption is 7.5%, based on the weight of the uncoated The coated braided suture is then wound onto a tempering frame under moderate tension and heated to 80 ° C. under nitrogen for 7 minutes.

Examination of the material with the aid of the roughness determination test described above using the specified device shows that the suture material has a roughness value of 0.41 kg (0.9 lbs.) In the dry state and of 1, 45 kg (3.2 lbs.) In the moist state (after immersion in water for 1 minute), so the comparable values for an uncoated control seam material are 2.95 kg (6.5 lbs.) In the dry state or 2.72 kg (6.0 lbs.) When wet.

When tested using a subjective scale ranging from 0 to 10 (where 0 is the roughest 55 material comparable to the uncoated, braided lactide / glycolide suture (10/90), and rating 10 is the same) corresponds to smoothest material, which is comparable to a braided polyethylene terephthalate material coated with polytetrafluoroethylene), the coated braided suture material shows an evaluation number of 10 in the dry state and an evaluation number of 8 in the wet state in a single knot tightening test.

The tensile strength of the coated, braided suture 65 material is 4.85 kg (10.7 lbs.) In the untied state and 2.68 kg (5.9 lbs.) In the tied state. The uncoated control material shows values of 5.26 kg (11.6 lbs.) And 2.86 kg (6.3 lbs.).

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Samples of coated and uncoated sutures are sterilized with ethylene oxide and implanted in animals. After 21 days, the tensile strength of the coated sutures is the same as that of the uncoated control materials. After 90 days, the coated suture was completely absorbed, with the tissue response at the lower end of the weak response category.

Example 2

40 parts by weight of a vinyl acetate / crotonic acid copolymer (90/10), 40 parts by weight of hydrogenated castor oil and 20 parts by weight of solid polyethylene glycol (with a molecular weight of about 20,000) are dissolved in 900 parts by weight 1 , 1,2-trichloroethane with stirring and maintaining a temperature of 35 ° C, whereby a solution with a total solids content of 10 wt .-% (weight / weight) is obtained. Untempered, braided suture size 2-0 (which is similar to the material of Example 1) is coated with this solution and dried as described in Example 1) in a drying tower and then on a spool in a vacuum. The solids uptake is 7.7%.

The coated sutures are then subjected to a further drying step by winding the coated and dried braided material from the spool onto tempering frames and exposing the wound, braided material to a vacuum of 100) in mercury for several days. The tempering frames are then transferred to a tempering furnace with the exclusion of air as possible and annealed under nitrogen.

Using the test methods described in Example 1, the roughness values in the dry and in the wet state were 0.32 kg (0.7 lbs.) And 1.68 kg (3.7 lbs.), Respectively, during the test uncoated control material gives values of 2.63 kg (5.8 lbs.) or 2.54 kg (5.6 lbs.).

The subjective ratings (using the 0 to 10 rating scale described above) give a 9 to 10 rating when dry and a 4 rating when wet compared to 0 and 0 for the uncoated control materials, respectively.

The tensile strength when pulling straight (not knotted) and pulling with a knot is 4.81 kg (10.6 lbs.) And 2.59 kg (5.7 lbs.). The in vivo investigations by implantation in animals lead to results which are similar to those of Example 1.

Example 3

28 parts by weight of an L - (-) - lactide / glycolide copolymer with a molar ratio of 65/35 (intrinsic viscosity = 3.9), 28 parts by weight of hydrogenated castor oil and 56 parts by weight of solid polyethylene glycol are dissolved (with a molecular weight of about 20,000) in 1488 parts by weight of 1,1,2-trichloroethane with stirring and while maintaining a temperature of about 35 ° C, whereby a solution with a total solids content of 7 wt .-% (weight / Weight). Then annealed, braided suture of size 2-0, which is similar to that of Example 1, is passed through the solution in the manner described in Example 1. The fibers are passed between the folds of a felt pad placed on or slightly above the surface of the solution to prevent the solution from being entrained with the exiting fiber due to the high viscosity of the solution. The drying and the subsequent short heat treatment are carried out similarly to the manner described in Example 1, with the difference that the mixture is heated to 82 ° C. for 7 lA minutes. The solids uptake is 6%.

In the roughness test using the device described above, the suture showed roughness-5 values of 0.68 kg (1.5 lbs.) (Dry) and 1.36 kg (3.0 lbs.) (Moist). The subjective test in the manner described in Example 1 gives evaluation numbers from 9 to 10 (dry) or 5 (wet).

The tensile strength values of the coated suture materials are 4.72 kg (10.4 lbs.) (Untied) and 2.68 kg (5.9 lbs.) (Tied), while the uncoated suture materials have values of 5.22 kg ( 11.5 lbs.) Or 2.90 kg (6.4 lbs.).

After sterilization, the coated suture materials are implanted in animals. The decrease in tensile strength is normal and the absorption is complete in 90 days. There is only a minimal tissue reaction.

Example 4

20 The solution described in Example 3 and the methods given there are used to coat annealed, braided sutures of size 2-0, which are similar to those described in Example 2. Drying and tempering are carried out according to the procedure described in Example 2. The roughness values read on the instrument are 0.68 kg (1.5 lbs.) (Dry) and 0.68 kg (1.5 lbs.) (Moist). The subjective values are 4 to 8 (dry) and 4 (wet). The tensile strength values are 5.12 kg (11.3 lbs.) (Untied) and 2.81 kg 30 (6.2 lbs.) (Tied), while the uncoated suture material values are 5.08 kg (11.2 lbs.) or 2.86 kg (6.3 lbs.).

If the sterilized samples are implanted in animals, absorption profiles are obtained which are similar to those of Examples 351 to 3.

Although the above description and examples are based on the coating of absorbable, multifilament sutures, it is understood that the coating can also be applied with good results on absorbable, monofilament sutures as well as on non-absorbable monofilament and multifilament sutures.

As already mentioned, catgut and collagen are among the most popular absorbable, monofilament sutures used today. These sutures are typically stored in an aqueous storage fluid to maintain the softness and flexibility of the suture. The preparation according to the invention can be used to coat such sutures, care being taken that the sutures in this way are not stored or packaged in a storage fluid which detaches and removes the covering from the suture during storage. In general, it is preferred to pack the coated catgut and collagen sutures in a moist state with little or no free fluid. Alternatively, you can use storage fluids in the suture material packs that are not solvents for the coating, or you can even use concentrated solutions of the coating preparation itself for this. Non-absorbable sutures, such as sutures made of cotton, linen, silk, polyester terephthalate and polyolefins, are normally coated with non-absorbable preparations. The polyolefins are usually used with a monofilament structure, 65 while cotton, linen, silk and polyester are usually processed into braided, twisted or covered multifilament sutures. Although it is not normally necessary to coat such

If sutures can be absorbed, the preparation according to the invention can, if desired, be used as a lubricant layer without any problems.

In the above examples, the coating solution was applied to the finished suture and the coating layer was formed at least on the outer surfaces of the outermost threads of the braided material. However, it is understood that the coating solution may be applied to the individual, if desired

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Threads can be applied before they are made into strands, or that they can be applied to the individual strands before they are made into the end seam material. Furthermore, all the examples were carried out with a 5 braided suture of size 2-0, which was only for convenience, so that the invention is not restricted to this suture size, but instead was applied, for example, to sutures with sizes from 8-0 to size 2 and larger can be.

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1 sheet of drawings

Claims (10)

635 244 PATENT CLAIMS (1) 10 to 50% by weight of a lactide / glycolide mixed polymer as an absorbable film former, (1) an absorbable film former selected from homopolymers and copolymers of lactide, homopolymers and copolymers of glycolide, copolymers of vinyl acetate with unsaturated carboxylic acid, water-soluble or water-dispersible cellulose derivatives, natural gums or resins, crystalline ethylene oxide polymers with high molecular weight, polyacrylamide Polyvinyl alcohol, polyvinyl pyrrolidone, gelatin, collagen, polyamino acids and conjugated unsaturated triglycerides; Surgical suture material, characterized in that it is coated with an absorbable composition which improves its knotting properties and which 2nd Coating mixture, which contains the aforementioned components (1), (2) and (3) and an amount of a liquid, volatile carrier which makes up 70 to 97% of the total weight of the coating mixture, covers a multi-piece surgical suture material with this coating mixture and removes the liquid, volatile carrier from the coating by volatilization. (2) 20 to 60% by weight of a polyethylene glycol with a weight average molecular weight between 5,000 and 50,000 as an absorbable lubricant and 2. Suture material according to claim 1, characterized in that the coating contains, as an absorbable film former, a lactide / glycolide copolymer which consists of 65 mol% dilactyl units and 35 mol% diglycolyl units. (2) as an absorbable lubricant, a polyalkylene glycol with a weight average molecular weight of less than 200,000; and (3) contains 10 to 40% by weight of hydrogenated castor oil as an absorbable, hydrophobic substance. 10. A method for producing a surgical suture material according to claim 1, the coating of which improves the knotting properties by 10 to 50% by weight of the absorbable film former (1), 20 to 60% by weight of the absorbable lubricant (2) and 10 to 40 wt .-% of the absorbable hydrophobic material (3), characterized in that a flowable 3. Suture material according to claim 1, characterized in that the coating contains, as an absorbable film former, a vinyl acetate / crotonic acid copolymer which consists of 10 mol% crotonic acid monomer units and 90 mol% vinyl acetate monomer units. (3) contains a higher fatty acid and / or an ester of a higher fatty acid as an absorbable hydrophobic material. 4. Suture material according to claim 1, characterized in that the coating contains drained castor oil as an absorbable film former. 5. Suture material according to claim 1, characterized in that the coating contains as polyalkylene glycol (2) a homopolymer of ethylene oxide or of propylene oxide and / or a copolymer of ethylene oxide with propylene oxide. 6. Suture material according to claim 1, characterized in that the coating contains as polyalkylene glycol (2) a poly-ethylene glycol with a weight average molecular weight between 5000 and 50,000. 7. Suture material according to claim 1, characterized in that the coating contains stearic acid as the higher fatty acid. 8. Suture material according to claim 1, characterized in that the coating contains sorbitan tristearate and / or hydrogenated castor oil as an ester of a higher fatty acid. 9. A synthetic, absorbable, multifilament, surgical suture material according to claim 1 made from a homopolymer of lactide or glycolide or a copolymer of lactide and / or glycolide, characterized in that it is coated with an absorbable preparation which improves its knotting properties and which 10th